def greet_user(username):
    """显示简单的问候语"""
    print("Hello, " + username.title() + "!")


greet_user('lexiaoyuan')


def get_formatted_name(first_name, last_name):
    """ 返回整洁的姓名 """
    full_name = first_name + ' ' + last_name
    return full_name.title()


while True:
    print("\nPlease tell me your name:")
    print("(enter 'q' at any time to quit)")

    f_name = input("First name:")
    if f_name == 'q':
        break

    l_name = input("Last name:")
    if l_name == 'q':
        break

    formatted_name = get_formatted_name(f_name, l_name)
    print("\nHello, " + formatted_name + "!")
